Pestology Blog
Tick Dispersal, Cat Flea Larvae Locomotion, and Wild Pig Management
Fairfax, VA – April 6, 2026
In this month's episode, the team covers new research on the links between tick dispersal and disease transmission, the secretes behind cat flea larva locomotion, and new data on wild hog management. We're joined by special guest Russ Ives of Rose Pest Solutions in Michigan!
Featured Article Summaries
Birds and Tick Dispersal
From Flyways to Foci: A Systematic Review and Meta-analysis On the Role of Birds in the Maintenance and Global Dispersal of Ticks and Tick-borne Pathogens
Tick-borne disease is a rising global public health threat, especially in the face of warming global temperatures and the increasing spread of invasive species. But the question is, how do these invasive species get to these places across the globe? And what new pathogens are they bringing along with them? Previous research suggested that the arrival of the new-to-North-America Asian Longhorned Tick (Haemaphysalis longicornis) may be associated with migratory birds. However, the level of threat of new ticks and tick-borne pathogens that these mass migrations could bring was unclear. The researchers therefore decided to do a global synthesis of evidence by combining data from 772 studies, 1268 georeferenced records, 34 avian orders, 185 tick species, and 102 pathogen species. There were 96 countries represented in the birds and bird-associated ticks data, and 79 countries represented the tick-associated pathogen data.
So after this synthesis of the global data, what did the researchers find? First, birds with recorded tick contact were mostly concentrated in Europe with 30.8%, North America at 25%, and South America with 20.4%. When broken down by bird species, tick records were most reported in the songbirds at 57.6%, followed by landfowl at 20.1%, and then shorebirds at 14.8%. When they looked at the geographical distribution of the ticks themselves, the Ixodes ticks (blacklegged or deer ticks and cousins) were the most reported group in Europe and North America, while Amblyomma ticks (like the Lone Star tick and cousins) were the majority in South America, and the Haemaphysalis ticks (like the Asian Longhorned tick and cousins) were the most reported in Asia. In terms of the pathogens that the ticks carried, bacterial pathogens were the most diverse and the most widely distributed. Borreliaceae were the most reported group at 56.1%, which is the same group that hosts Borrelia burgdoferi, which is the causative agent of Lyme Disease. Viruses were also common and were almost exclusively detected in the Northern hemisphere. Interestingly, the researchers discovered a high prevalence of pathogens at 21 species despite the small sample size at 26 for Asia, suggesting that the tick-borne pathogens in that area are understudied.
The researchers also found that the songbirds were the species that hosted the greatest tick diversity with 129 species documented. Of these, most of the tick species associated included the Ixodes genera and the Amblyomma genera. Both genera are well-known for hosting ticks that transmit pathogens to humans, such as the Blacklegged Tick, and the Lone Star Tick. However, as far as infestation prevalence went, or the group of birds that was most likely to present with an associated tick, the landfowl took that crown with 17.6% infested, which importantly, includes domesticated chickens.
When the researchers looked at the pathogens associated with these ticks that were hitching a ride on these birds, they found a total of 102 pathogen species from 21 genera. Of these, 55 species, or 53.9%, were recognized as pathogens that had the potential to infect humans and cause illness. When the researchers examined the breakdown, they found the ticks associated with the songbirds featured the highest diversity of pathogens with 20 associated pathogens, followed by shorebirds with 18, and landfowl with 15.
Finally, the researchers were able to map migratory pathways with all this metadata, and found that there were non-native tick introductions that could be traced along the same pathways. This study emphasizes that birds likely have a large role in tick dispersal, and by proxy, the dispersal of pathogens that are associated with ticks. Many of the birds highlighted in this study are those that have frequent contact with humans and urban or semi-urban environments, which emphasizes the potential for the spread of tick-borne pathogens.
Article by Laura Rosenwald, BCE
References
Flea Locomotion
The Mechanics of Larval Cat Flea Locomotion
The cat flea can be a challenging pest to control. Mainly due to the fact that successful management often requires addressing both adult and immature populations. Which can be tough since adults and immatures aren’t often found in the same place. The adults, as ectoparasites, spend most of their time on their preferred host feeding on blood. As they feed, the adult fleas regularly pass semi-digested blood as waste that falls to the ground to serve as the primary food source for flea larvae.
Extensive research has been conducted to better understand the biology and behavior of adult cat fleas over the decades. Investigating the mechanisms of adult flea locomotion has led to a broader understanding of how fleas move in an environment, their potential capacity and range for dispersal, and how they interact with their hosts. However, the same attention hasn’t been given to the larval stage. It’s known that the immature life stages are typically found in areas where their target hosts frequent, and they will actively move in search of food, more desirable environmental conditions, or to avoid cannibalism. But their capacity for locomotion and the mechanics behind it weren’t widely agreed upon in literature. Until now.
Enter researchers Adriana Smith, Jacob Norton, Christina McDonald, and Matt Bertone. This collaborative research team from NC State and Georgia Tech set out to solve the mysteries of larval flea locomotion. The technology that was largely credited with breakthroughs in breaking down adult flea locomotion was high-speed cameras. Following a similar playbook, the NC State and Georgia Tech team used the same videography equipment combined with scanning electron microscope imaging to document and track larval flea movement.
Shooting at 600 frames per second, the team captured nine different sequences of larval movement on a flat surface across all three larval instars. They also filmed similar movement sequences as larvae navigated polyester fiber rugs. This was used to provide qualitative data that they would use to describe HOW the larvae were moving through their environment. To measure how fast the larvae were able to navigate their environment, the researchers tracked 49 larvae at +300 frames per second while moving across plane paper (Figure 1).
Thanks to the highspeed footage, the researchers were able to properly define and describe the mechanics of larval locomotion. For all three instars, the larvae move by extending their head and pulling the rest of their body forward in a crawl, using their maxillary palps to grip and gain traction. From the high-tech imagery, the authors concluded that labial pals, mandibles, and anal struts were not involved in locomotion as older publications had suggested. However, they did note that downward projecting hairs and anal struts were important in balancing the larvae as they moved to prevent them from barrel rolling.
The author’s detailed dissection of larval locomotion was informative, and I did find it interesting. But what really stood out to me from this study was the breakdown of how FAST these tiny larvae could move. Across all three instars, larvae traveled between 0.36 – 1.14 body lengths per second (Figure 1). At 1.14 BL/S, that’s the equivalent of approximately 4.3 miles per hour. For comparison, the average human walks at about 3 miles per hour. That’s surprisingly fast for something so small! And, it really changes my perception of the potential range of cat flea larvae in the environment. Something with the capacity to travel so quickly could certainly cover a lot more ground that I gave this pest credit for in the past, and could justify expanding your inspection footprint both indoors and out during your next flea job.
The behavior and speed of larval locomotion of cat fleas. A) Selected frames from a video sequence captured at 600 frames per second showing the sequential steps and timing of a single head pulling movement. Blue inset box corresponds to close-up view in lower left showing maxillary palps as they first interact with the substrate. B) Head pulls (the repetitive movement used by larvae to move forward) per second across instar represented in median (line), upper and lower quartile, and range. Points represent independent individual samples. C) Millimeters traveled per second across instar represented in median (line), upper and lower quartile, and range. Points represent independent individual samples. Different lowercase letters indicate statistical differences between groups according to post hoc tests between pairs (see “Methods” and “Results” section).
Article by Mike Bentley, PhD, BCE
Adrian A Smith, Jacob J Norton, Christina L McDonald, Matthew A Bertone, The mechanics of larval cat flea locomotion (Siphonaptera: Pulicidae), Journal of Insect Science, Volume 26, Issue 1, January 2026, ieaf115, https://doi.org/10.1093/jisesa/ieaf115
Wild Hog Control
Spatial Behavior of Socially Isolated Wild Pigs (Sus Scrofa) Following Sounder Removal Via Trapping
Wild hogs are an invasive species in the US with a spreading range of many of the southern states. As is the case with most invasive species, they cause many problems for people and the environment here. They can be destructive to farms and property, and dangerous to livestock and people. They are capable to spreading diseases to livestock and there are a variety of efforts put in place to keep their populations down and prevent their spread. While many PMPs focus mainly on insect and rodent pests, there are plenty who include wildlife to their business or focus on it entirely. Wild hog control can be highly specialized so in areas of the US where they are prevalent, wildlife control services can be critical to the function of farms and communities staying safe from these invasive pests.
Trapping is one of the main control methods folks use including whole sounder removal. A sounder, for reference, is a social family or group of feral hogs. This can get complicated though because it can be hard to get the whole group and not leave off one or two that will just recolonize and repopulate. It’s kind of like getting the whole ant colony. The behavior of the remaining hogs determines how well those removal efforts work to affect the entire population as a whole. This study focused on what happens to the ones left behind when attempting a sounder removal. What would the remaining hogs do spatially and temporally when their family was gone?
The study took place in Alabama around farmland and mixed-use land. They did their best to collect and trap a whole sounder then they selected an adult female to tag and release after they removed the rest of the sounder. The tag collars helped track several behavioral movements of the pig like how fast they moved and where they went. They were able to tell if the hog was moving cautiously or swiftly, if its daily range changed or moved, etc. They monitored the behavior for a month in greater detail post trapping and then more infrequently over 138 days for longer term data.
Fig. 1. Spatial layout of wild pig (S. scrofa) study sites and trap set up. (A) Map of Alabama showing five focal counties (Bullock, Russell, Dale, Henry and Geneva) used for GPS-collar deployment on wild pigs between 2022 and 2023. Shaded areas indicate counties where wild pigs were GPS-collared following sounder removal events. Black stars mark approximate capture sites. (B) Field photograph of the corral-style trap used for live captures of wild pigs, illustrating the guillotine-style door, panel configuration, and surrounding habitat.
So here is what they found. Unsurprisingly, the individuals varied greatly in their behavior, as is such with many wild animals, some were more cautious some moved around more, some stayed home and avoided humans more. Scientists call this kind of variation, spatial personality. About half the pigs stayed within a km of the original trap site, the furthest travel was 6km and very few were going that far. Compared to other studies, this was a smaller range of movement. This means that the social isolation is likely to make the individual move around less. They generally exhibited no major changes in how much space usage post collaring as opposed to unencumbered individuals with intact sounders. The location of the space used did alter some, basically to say they shifted locations a bit but didn’t start moving around a larger area. There are also levels of complication on how some pigs were taken from more female dominated groups and those individuals (remember we picked females) moved further from the trap area. Questions such as the gender dynamics of sounder behavior leave further research to be explored.
Anyways! What do we conclude? Remember we worry about pigs infecting other animals with disease, so we think of the likelihood of an infected pig isolated from its sounder, is unlikely to travel far from the trapped area and infect far away livestock. This is a good thing. Most pigs aren’t going far so that means that you could search the same vicinity to try and track down any stragglers from an estimated sounder capture. This emphasizes that whole sounder removal is a valid technique and is unlikely to put the rest of the area at risk from the potential few strays. Of course, this data is limited to females which are of more concern if escaped.
Article by Ellie Sanders, BCE
References
Gomez-Maldonado, S., McDonough, M.T., Valente, J.J., Smith, M.D. and Ditchkoff, S.S. (2026), Spatial behavior of socially isolated wild pigs (Sus scrofa) following sounder removal via trapping. Pest Manag Sci. https://doi.org/10.1002/ps.70630
Listen to the Episode!
Have questions or feedback for the BugBytes team? Email us at training@pestworld.org, we'd love to hear from you!
